package cn.itcast.hotel.service.impl;

import cn.itcast.hotel.mapper.HotelMapper;
import cn.itcast.hotel.pojo.Hotel;
import cn.itcast.hotel.pojo.HotelDoc;
import cn.itcast.hotel.pojo.PageResult;
import cn.itcast.hotel.pojo.RequestParams;
import cn.itcast.hotel.service.IHotelService;
import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {
    @Autowired
    private RestHighLevelClient client;

    /**
     * 分页、排序、地图距离显示
     *
     * @param params
     * @return
     */
    @Override
    public PageResult search(RequestParams params) {
        try {
//        1.准备request
            SearchRequest request = new SearchRequest("hotel");
//        2.准备DSL
//        2.1.query
//            构建BooleanQuery
            buildBasicQuery(params, request);
//        2.2.分页
            int page = params.getPage();
            int size = params.getSize();
            request.source().from((page - 1) * size).size(size);
//        2.3.排序
            String location = params.getLocation();
            if (location != null && !"".equals(location)) {
                request.source().sort(SortBuilders
                        .geoDistanceSort("location", new GeoPoint(location))
                        .order(SortOrder.ASC)
                        .unit(DistanceUnit.KILOMETERS)
                );
            }
//        3.发送请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//        4.解析响应
            return handelResponse(response);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 搜索列表信息
     *
     * @param params
     * @return
     */
    @Override
    public Map<String, List<String>> filters(RequestParams params) {
        try {
//        1.准备request
            SearchRequest request = new SearchRequest("hotel");
//        2.准备DSL
//        2.1.query
            buildBasicQuery(params, request);
//        2.2.设置size，去掉文档
            request.source().size(0);
//        2.3.聚合
            buildAggregation(request);
//        3.发送请求，接收响应
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//        4.解析响应结果
            Map<String, List<String>> result = new HashMap<>();
            Aggregations aggregations = response.getAggregations();
            //        4.1.根据品牌名称，获取品牌结果
            List<String> brandList = getAggByName(aggregations, "brandAgg");
            result.put("brand", brandList);
            //        4.2.根据城市名称，获取城市结果
            List<String> cityList = getAggByName(aggregations, "cityAgg");
            result.put("city", cityList);
            //        4.3.根据星级名称，获取星级结果
            List<String> starList = getAggByName(aggregations, "starAgg");
            result.put("starName", starList);
//            5.返回结果
            return result;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 搜索框自动补全
     *
     * @param prefix
     * @return
     */
    @Override
    public List<String> getSuggestions(String prefix) {
        try {
//        1.准备request
            SearchRequest request = new SearchRequest("hotel");
//        2.准备DSL
            request.source().suggest(new SuggestBuilder()
                    .addSuggestion("suggestions",
                            SuggestBuilders.completionSuggestion("suggestion")
                                    .prefix(prefix)
                                    .skipDuplicates(true)
                                    .size(10))
            );
//        3.发送请求，接受响应
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//        4.解析结果
            Suggest suggest = response.getSuggest();
//        4.1.根据补全查询名称获取查询结果
            CompletionSuggestion suggestions = suggest.getSuggestion("suggestions");
//        4.2.获取options
            List<CompletionSuggestion.Entry.Option> options = suggestions.getOptions();
//        4.3.遍历
            List<String> list = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option : options) {
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * es删除
     *
     * @param id，酒店id
     */
    @Override
    public void deleteById(Long id) {
        try {
//        1.准备request
            DeleteRequest request = new DeleteRequest("hotel", id.toString());
//        2.发送请求
            client.delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * es新增和修改
     *
     * @param id，酒店id
     */
    @Override
    public void insertById(Long id) {
        try {
//        0.根据id查询酒店数据
            Hotel hotel = getById(id);
//        转换为文档类型
            HotelDoc hotelDoc = new HotelDoc(hotel);
//        1.准备request对象
            IndexRequest request = new IndexRequest("hotel").id(hotel.getId().toString());
//        2.准备json文档
            request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
//        3.发送请求
            client.index(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private List<String> getAggByName(Aggregations aggregations, String aggName) {
        //        4.1.根据聚合名称获取聚合结果
        Terms brandTerms = aggregations.get(aggName);
//        4.2.获取buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
//        4.3.遍历
        List<String> brandList = new ArrayList<String>();

        for (Terms.Bucket bucket : buckets) {
//            4.4.获取key
            String key = bucket.getKeyAsString();
            brandList.add(key);
        }
        return brandList;
    }

    /**
     * 抽取的聚合函数
     *
     * @param request
     */
    private void buildAggregation(SearchRequest request) {
        request.source().aggregation(AggregationBuilders
                .terms("brandAgg")
                .field("brand")
                .size(100));
        request.source().aggregation(AggregationBuilders
                .terms("cityAgg")
                .field("city")
                .size(100));
        request.source().aggregation(AggregationBuilders
                .terms("starAgg")
                .field("starName")
                .size(100));
    }

    private void buildBasicQuery(RequestParams params, SearchRequest request) {
//        1.构建boolQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
//            must部分，关键字搜索
        String key = params.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all", key));
        }
//            条件过滤
//            城市条件
        if (params.getCity() != null && !params.getCity().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("city", params.getCity()));
        }
//            品牌条件
        if (params.getBrand() != null && !params.getBrand().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("brand", params.getBrand()));
        }
//            星级条件
        if (params.getStarName() != null && !params.getStarName().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("starName", params.getStarName()));
        }
//            价格范围
        if (params.getMinPrice() != null && params.getMaxPrice() != null) {
            boolQuery.filter(QueryBuilders
                    .rangeQuery("price").gte(params.getMinPrice()).lte(params.getMaxPrice()));
        }
//      2.算分控制
        FunctionScoreQueryBuilder functionScoreQuery =
                QueryBuilders.functionScoreQuery(
//                        原始查询，相关性算分查询
                        boolQuery,
//                        function scope的数组
                        new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
//                                其中的一个function score元素
                                new FunctionScoreQueryBuilder.FilterFunctionBuilder(
//                                        过滤条件
                                        QueryBuilders.termQuery("isAD", true),
//                                        算分函数
                                        ScoreFunctionBuilders.weightFactorFunction(10)
                                )
                        });
        request.source().query(functionScoreQuery);
    }


    private PageResult handelResponse(SearchResponse response) {
        //        4.解析响应
        SearchHits hits = response.getHits();
//        4.1.获取总条数
        long total = hits.getTotalHits().value;
//        4.2.文档数组
        SearchHit[] hitsHits = hits.getHits();
//        4.3.遍历数组
        List<HotelDoc> hotels = new ArrayList<>();
        for (SearchHit hitsHit : hitsHits) {
//            获取文档source
            String json = hitsHit.getSourceAsString();
//            反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
//            获取排序值
            Object[] sortValues = hitsHit.getSortValues();
            if (sortValues.length > 0) {
                Object sortValue = sortValues[0];
                hotelDoc.setDistance(sortValue);
            }
            hotels.add(hotelDoc);
        }
//        4.4.封装返回
        return new PageResult(total, hotels);
    }
}
